A rack apparatus that holds and encloses electronic devices is widely used. Various proposals to improve such a rack apparatus are known (for example, Japanese Laid-Open Patent Publication No. 2003-142859).
The above rack apparatus sometimes holds and encloses a plurality of articles, for example, electronic devices such as a server device and a tape library device, one just above the other. The electronic devices enclosed in the rack apparatus are sometimes attached to rail devices, for maintenance and inspection of the electronic devices.
When articles are held in vertically-arranged tiers, the work on an article held in a tier may be interfered with by an article held in another tier.